[Cryptech Tech] USB interface

[Peter Stuge]

Rob Austein wrote:
> > In particular those who already use rev03 in production - how do
> > applications currently handle the device suddenly becoming
> > unresponsive?
> 
> RPC hangs or closes, management console hangs or closes.  Would have
> to check code to see which in each case, and as we have multiple
> client implementations the answers might not be uniform.  Clients are
> of course free to time out, in which case they must consider the
> existing RPC stream to be toast.
> 
> Given that we're talking about new HSM behavior where the USB device
> vanishes from the host OS, the current MUX might just close all
> connections.

Ok, yes, an explicit error seems better than "hangs".

I was unsure about the self-powered behavior but I think it's really desirable.


> > Related to that: What happens with RPC session ids (is that the right name?)
> > across a rev03 disconnect+connect?
> 
> HSM loses all knowledge of current sessions when power cycled.

I agree strongly with this.


> So recovery options after an HSM power cycle are pretty limited.

Especially since the host can never really tell for sure from "hangs"
that a power cycle happened, except by guessing based on a timeout.


Thanks!

//Peter